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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive for
* more details.
*
* Copyright (C) 2025 Kalray Inc.
* Author(s): Julian Vetter <jvetter@kalrayinc.com>
*/
#include <stdarg.h>
#include <ucontext.h>
/* Number of arguments that go in registers. */
#define NREG_ARGS 12
/* Take a context previously prepared via getcontext() and set to
call func() with the given int only args. */
void
__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
{
extern void __startcontext (void);
unsigned long *funcstack;
va_list vl;
unsigned long *regptr;
unsigned int reg;
/* Start at the top of stack. */
funcstack = (unsigned long *) (ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
funcstack -= argc < NREG_ARGS ? 0 : argc - NREG_ARGS;
funcstack = (unsigned long *) (((uintptr_t) funcstack & -32L));
ucp->uc_mcontext.sc_regs.r12 = (unsigned long) funcstack;
/* Use $r20 and $r21 to pass some infos to __startcontext */
ucp->uc_mcontext.sc_regs.r20 = (unsigned long) ucp->uc_link;
ucp->uc_mcontext.sc_regs.r21 = (unsigned long) func;
ucp->uc_mcontext.sc_regs.ra = (unsigned long) __startcontext;
va_start (vl, argc);
/* The first twelve arguments go into registers. */
regptr = &(ucp->uc_mcontext.sc_regs.r0);
for (reg = 0; (reg < argc) && (reg < NREG_ARGS); reg++)
*regptr++ = va_arg (vl, unsigned long);
/* And the remainder on the stack. */
for (; reg < argc; reg++)
*funcstack++ = va_arg (vl, unsigned long);
va_end (vl);
}
weak_alias (__makecontext, makecontext)
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